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China Communications 2024年第3期21卷 260-272页

作者： Zhang Mengjiao Liu Yu Huang Jie he ruisi Zhang Jingfan Yu Chongyang Wang Chengxiang School of Microelectronics Shandong UniversityJinan 250101China The State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong UniversityBeijing 100044China The National Mobile Communications Research Laboratory School of Information Science and EngineeringSoutheast UniversityNanjing 210096China The Purple Mountain Laboratories Nanjing 211111China

A large amount of mobile data from growing high-speed train(HST)users makes intelligent HST communications enter the era of big *** corresponding artificial intelligence(AI)based HST channel modeling becomes a *** paper provides AI based channel characteristic prediction and scenario classification model for millimeter wave(mmWave)HST ***,the ray tracing method verified by measurement data is applied to reconstruct four representative HST *** setting the positions of transmitter(Tx),receiver(Rx),and other parameters,the multi-scenarios wireless channel big data is ***,based on the obtained channel database,radial basis function neural network(RBF-NN)and back propagation neural network(BP-NN)are trained for channel characteristic prediction and scenario ***,the channel characteristic prediction and scenario classification capabilities of the network are evaluated by calculating the root mean square error(RMSE).The results show that RBF-NN can generally achieve better performance than BP-NN,and is more applicable to prediction of HST scenarios.

关键词： artificial intelligence channel characteristic prediction HST channel millimeter wave scenario classification

Modeling and Channel Estimation for Piezo-Acoustic Backscatter Assisted Underwater Acoustic Communications

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China Communications 2022年第11期19卷 297-307页

作者： Junliang Lin Gongpu Wang Zijian Zheng Ruyi Ye ruisi he Bo Ai School of Computer and Information Technology Beijing Jiaotong UniversityBeijing 100091China School of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing 100091China China National Institute of Standardization Beijing 100088China The State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong UniversityBeijing 100091China

Relying on direct and converse piezoelectric effects,piezo-acoustic backscatter(PAB)technology reflects ambient acoustic signals to enable underwater backscatter communications at near-zero power,which was first realized through a *** this paper,we propose a mathematical model of the PAB assisted underwater acoustic(UWA)communication,and address the sparse channel estimation ***,we present a five-stage backscatter process to derive the backscatter coefficient,and propose the channel model for the shallow-water ***,we formulate the shallow-water acoustic channel estimation problem as a sparse vector recovery one according to the compressed sensing theory,and leverage the orthogonal matching pursuit(OMP)algorithm to obtain the channel ***,simulation results are provided to corroborate our proposed studies.

关键词： channel estimation compressed sensing piezo-acoustic backscatter underwater acoustic communications

OTFS Modulation and PAPR Reduction for IoT-Railways

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China Communications 2023年第1期20卷 102-113页

作者： Huichao Shang Ruifeng Chen Haoxiang Zhang Guoyu Ma ruisi he Bo Ai Zhangdui Zhong State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong UniversityBeijing 100044China Institute of Computing Technologies China Academy of Railway Sciences Co.Ltd.Beijing 100081China China Academy of Industrial Internet Ministry of Industry and Information TechnologyBeijing 100804China

The internet of things(IoT)has been widely considered to be integrated with high-speed railways to improve safety and *** is important to achieve reliable communication in IoT for railways(IoT-R)under high mobility scenarios and strict energy *** time frequency space(OTFS)modulation is a two-dimensional modulation technique that has the potential to overcome the challenges in high Doppler *** addition,OTFS can have lower peak-to-average power ratio(PAPR)compared to orthogonal frequency division multiplexing,which is especially important for the application of ***,OTFS modulation for IoT-R is investigated in this *** order to decrease PAPR of OTFS and promote the application of OTFS modulation in IoT-R,the peak windowing technique is used in this *** technique can reduce the PAPR of OTFS by reducing the peak power and does not require multiple *** impacts of different window functions,window sizes and clipping levels on PAPR and bit error rate of OTFS are simulated and *** simulation results show that the peak windowing technique can efficiently reduce the PAPR of OTFS for IoT-R.

关键词： internet of things for railways(IoT-R) orthogonal time frequency space(OTFS) peak-toaverage power ratio(PAPR) peak windowing

Multi-Scenario Millimeter Wave Wireless Channel Measurements and Sparsity Analysis

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China Communications 2022年第11期19卷 16-31页

作者： Hang Mi Bo Ai ruisi he Xin Zhou Zhangfeng Ma Mi Yang Zhangdui Zhong Ning Wang State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong UniversityBeijing 100044China henan Joint International Research Laboratory of Intelligent Networking and Data Analysis Zhengzhou UniversityZhengzhou 450001China PengCheng Laboratory Shenzhen 518000China National Institute of Metrology of China Beijing 100029China School of Information Engineering Zhengzhou UniversityZhengzhou 450001China

Wireless channel characteristics have significant impacts on channel modeling,estimation,and communication *** the channel sparsity is an important characteristic of wireless *** the sparse nature of wireless channels can reduce the complexity of channel modeling and estimation,and improve system design and performance *** with the traditional sub6 GHz channel,millimeter wave(mmWave)channel has been considered to be more sparse in existing ***,most research only assume that the mmWave channel is sparse,without providing quantitative analysis and ***,this paper evaluates the sparsity of mmWave channels based on mmWave channel measurements.A vector network analyzer(VNA)-based mmWave channel sounder is developed to measure the channel at 28 GHz,and multi-scenario channel measurements are *** Gini index,Rician𝐾factor and rootmean-square(RMS)delay spread are used to measure channel ***,the key factors affecting mmWave channel sparsity are *** is found that antenna steering direction and scattering environment will affect the sparsity of mmWave *** addition,the impact of channel sparsity on channel eigenvalue and capacity is evaluated and analyzed.

关键词： channel sparsity channel measurement mmWave channel measures of sparsity

Generative Adversarial Networks Based Digital Twin Channel Modeling for Intelligent Communication Networks

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China Communications 2023年第8期20卷 32-43页

作者： Yuxin Zhang ruisi he Bo Ai Mi Yang Ruifeng Chen Chenlong Wang Zhengyu Zhang Zhangdui Zhong State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong UniversityBeijing 100044China Institute of Computing Technologies China Academy of Railway Sciences Co.Ltd.Beijing 100081China

Integration of digital twin(DT)and wireless channel provides new solution of channel modeling and simulation,and can assist to design,optimize and evaluate intelligent wireless communication system and *** DT channel modeling,the generated channel data can be closer to realistic channel measurements without requiring a prior channel model,and amount of channel data can be significantly *** intelligence(AI)based modeling approach shows outstanding performance to solve such *** this work,a channel modeling method based on generative adversarial networks is proposed for DT channel,which can generate identical statistical distribution with measured *** validation is conducted by comparing DT channel characteristics with measurements,and results show that DT channel leads to fairly good agreement with measured ***,a link-layer simulation is implemented based on DT *** is found that the proposed DT channel model can be well used to conduct link-layer simulation and its performance is comparable to using measurement *** observations and results can facilitate the development of DT channel modeling and provide new thoughts for DT channel applications,as well as improving the performance and reliability of intelligent communication networking.

关键词： digital twin channel modeling generative adversarial networks intelligent communication networking

Radio Communication Scenarios in 5G-Railways

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中国通信:英文版 2023年第9期20卷 235-246页

作者： ruisi he Bo Ai Zhangdui Zhong Mi Yang Chen Huang Ruifeng Chen Jianwen Ding Hang Mi Zhangfeng Ma Guiqi Sun Changzhu Liu State Key Lab of Rail Traffic Control and Safety Beijing Jiaotong UniversityBeijing 100044China Pervasive Communication Research Center Purple Mountain LaboratoriesNanjing 211111China Institute of Computing Technology China Academy of Railway SciencesBeijing 100081China College of Information Engineering Shaoyang UniversityShaoyang 422000China National Research Center of Railway Safety Assessment Beijing Jiaotong UniversityBeijing 100044China Key Laboratory of Railway Industry of Broadband Mobile Information Communications Beijing Jiaotong UniversityBeijing 100044China Beijing Engineering Research Center of High-speed Railway Broadband Mobile Communications Beijing Jiaotong UniversityBeijing 100044China

With the rapid development of railways,especially high-speed railways,there is an increasingly urgent demand for new wireless communication system for *** the mature 5G technology as an opportunity,5G-railways(5G-R)have been widely regarded as a solution to meet the diversified demands of railway wireless *** the design,deployment and improvement of 5GR networks,radio communication scenario classification plays an important role,affecting channel modeling and system performance *** this paper,a standardized radio communication scenario classification,including 18 scenarios,is proposed for *** paper analyzes the differences of 5G-R scenarios compared with the traditional cellular networks and GSM-railways,according to 5G-R requirements and the unique physical environment and propagation *** proposed standardized scenario classification helps deepen the research of 5G-R and promote the development and application of the existing advanced technologies in railways.

关键词： 5G-R scenario classification smart rail-ways

OTFSmodulation performance in a satellite-to-ground channel at sub-6-GHz and millimeter-wave bands with high mobility

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Frontiers of Information Technology & Electronic Engineering 2021年第4期22卷 517-526页

作者： Tianshi LI ruisi he Bo AI Mi YANG Zhangdui ZHONG Haoxiang ZHANG State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong UniversityBeijing 100044China China Academy of Industrial Internet Ministry of Industry and Information TechnologyBeijing 100804China

Orthogonal time frequency space(OTFS)modulation has been widely considered for high-mobility ***-to-ground communications have recently received much attention as a typical high-mobility scenario and face great challenges due to the high Doppler *** enable reliable communications and high spectral efficiency in satellite mobile communications,we evaluate OTFS modulation performance for geostationary Earth orbit and low Earth orbit satellite-to-ground channels at sub-6-GHz and millimeter-wave bands in both lineof-sight and non-line-of-sight *** minimum mean squared error with successive detection(MMSE-SD)is used to improve the bit error rate *** adaptability of OTFS and the signal detection technologies in satellite-to-ground channels are *** results confirm the feasibility of applying OTFS modulation to satellite-to-ground communications with high *** full diversity in the delay-Doppler domain can be explored,different terminal movement velocities do not have a significant impact on the performance of OTFS modulation,and OTFS modulation can achieve better performance compared with classical orthogonal frequency division multiplexing in satellite-to-ground *** is found that MMSE-SD can improve the performance of OTFS modulation compared with an MMSE equalizer.

关键词： Delay-Doppler channel High-mobility communications Minimum mean squared error with successive detection(MMSE-SD) Orthogonal time frequency space(OTFS) Satellite-to-ground communications Millimeter-wave communications

Introduction of Western Medicines into China and Improvement on Decoctions during Modern China

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Chinese Medicine and Culture 2024年第2期7卷 128-142页

作者： ZHU ruisi College of Humanities Zhejiang Normal UniversityJinhua 321004China

During the late Qing dynasty(1840 A.D.-1912 A.D.),a large quantity of Western medicines entered China,which continuously impacted the traditional Chinese medicine(TCM)market and revealed the shortcomings of Chinese *** personages in the TCM community followed the trend of learning from the West,and attempted to reform TCM,with the improvement on decoction becoming an important aspect of this *** debates and trials,the improvement on decoction underwent three stages of conceptual evolution:“taking Chinese medicines as the foundation and referring to the dosage forms of Western medicines”,“introducing Western techniques to serve the preparation of decoctions”and“integrating the theories of TCM and Western medicine to improve decoctions”.The study highlights the effective complementarity between modern TCM and Western medicine in the field of pharmacy,and provides valuable experience and support for the reevaluation of the value of TCM in contemporary society.

关键词： Western medicine Improvement Decoction Traditional Chinese medicine Scientization

Theory Analysis of the Handover Challenge in Express Train Access Networks （ETAN）

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China Communications 2014年第7期11卷 92-98页

作者： HU Guoqing HUANG Anpeng he ruisi AI Bo CheN Zhangyuan State Key Lab of Advanced Optical Communication Systems and Networks Peking University Beijing 100871 P. R. China State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University Beijing 100044 E R. China

To handle the handover challenge in Express Train Access Networks(ETAN).mobility fading effects in high speed railway environments should be addressed *** on the investigation of fading effects in this paper,we obtain two theoretical bounds:HOTiming upper bound and HO-Margin lower bound,which are helpful guidelines to study the handover challenge today and in the ***,we apply them to analyze performance of conventional handover technologies and our proposal in *** follow-up theory analyses and simulation experiment results demonstrate that the proposed handover solution can minimize handover time up to 4ms(which is the fastest one so far),and reduce HO-Margin to 0.16 dB at a train speed of 350km/h.

关键词：接入网络交接仪式特快列车切换技术环境影响高速铁路仿真实验切换时间

Multi-Frequency Channel Characterization for Massive MIMO Communications in Lobby Environment

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China Communications 2019年第9期16卷 79-92页

作者： Jianzhi Li Bo Ai ruisi he Mi Yang Zhangdui Zhong State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University

In this paper,a massive multiple input multiple output(MIMO)channel measurement campaign with two setups is conducted in an indoor lobby *** the first setup,two types of 256-element virtual uniform rectangular arrays(URAs),i.e.,the 4×64 virtual URA and the 64×4 virtual URA are *** carrier frequency is 11 GHz;in the second setup,measurements are performed at 4,6,11,13,15,18 GHz at two different user *** channel characterization is presented by investigating the typical channel parameters,including average power delay profile(APDP),K factor,root mean square(RMS)delay spread,and coherence ***,the channel characteristics in angular domain are investigated by applying the space-alternating generalized expectation-maximization(SAGE)*** extracted multipath components(MPCs)are preliminarily clustered by visual inspection,and related to the interacting objects(IOs)in physical *** structures at multiple frequency bands are *** spread of departure is estimated to evaluate the directional dispersion at the base station(BS)*** results in this paper can help to reveal the propagation mechanisms in massive MIMO channels,and provide a foundation for the design and application of the practical massive MIMO system.

关键词： 5G Massive MIMO channelmeasurement virtual array SAGE K factor RMS delay spread coherence bandwidth scatterer localization direction spread